In a display device such as a liquid crystal display device, for example, a transistor including a thin film transistor (TFT) for pixel selection is provided in each of a plurality of pixels arranged in a matrix form on a substrate such as a glass substrate.
When light is irradiated onto the transistor provided on the substrate as described above, a light leakage current flows in the transistor so that the quality of an image displayed in the display region is reduced. Therefore, a light shielding film for shielding the light from the backlight may be provided between the transistor and the substrate in order to prevent the flow of the light leak current by the irradiation of light from a backlight incident from a back side of the substrate onto the transistor provided on the substrate.
For example, Japanese Patent Application Laid-Open Publication No. 2007-201073 (Patent Document 1) describes a technique of forming a metal layer having a function of shielding a thin film transistor from the light on the substrate side such as a glass substrate or others on the substrate in a display device.